In automation systems, electro-pneumatic modular systems are used. A structure of individual modules is suitable in order to be able to construct custom-made systems for the user. Up to now, modules having a pure electronic function and modules having pneumatic functions have to be combined respectively to ensure the supply of the pneumatic modules with the control fluid. In a system expansion, it is thus possibly necessary to remove pneumatic modules to first connect electric modules—or vice versa.
A supply voltage is to be applied both to the electric and to the electro-pneumatic modules. Furthermore, the modules are connected to a control bus, for example to a field bus. When using a control bus system as is usual in automation technique, each individual module requires an address, and each module must be able to decode the signals on the control bus. In a harsh industrial environment with dust atmosphere and/or water, a mounting in a switch cabinet is necessary due to the plurality of line connections, since otherwise each connector would have to be sealed and the line insulations would have to meet the specific requirements. This is constructively complicated and thus expensive.
Due to the limitations mentioned above, there is a need for a modular system in which the electronic modules and the pneumatic modules can be mounted in line in any order.
There is further a need for a modular system in which the individual modules which can be mounted in line are encapsulated and can do with a minimum of external line connections such that a mounting in a switch cabinet becomes unnecessary.
There is further a need for a modular system which also allows the use of passive modules, i.e. of modules which cannot decode the serial data of a control bus, and which can however comprise a plurality of modules.